Tungsten Copper FGM Laser-heating Synthesis

At the beginning of 1990s, FGM (functionally graded material) has developed rapidly and additional temperature laser scanning sintering process has been introduced in FGM process. It solves the problem that the difference of sintering temperature and shrinkage of different composition gradient layers, which is difficult to conventional sintering technology furnace constant temperature sintering method. In addition, it shows laser heat source temperature gradient sintering non-polluting, high efficiency and the advantages of modernization.

However, the application of laser in tungsten copper FGM material research has just started, the researchers used a micro-thermocouple embedded successfully measured the sintering temperature of laser sintering of tungsten-copper gradient material distribution. In general, W-Cu gradient functional materials with no interfacial changes can be obtained by laser sintering process with large spot size; sintering process of tungsten - copper alloy synthesized by laser heating under the thermocouple dynamic measurement was analyzed, and the difference of sintering temperature and shrinkage difference of FGM were solved by laser heating; The microstructure of tungsten copper FGM shows macroscopic microstructures changes; the micro-hardness of the tungsten - copper functionally graded material synthesized by the laser - sintering process of the large - plate laser is gradient distribution, which satisfies the linear distribution rule; and laser heat synthesis process should be under inert gas such as argon or neon gas.

In addition, tungsten copper FGM mainly uses laminated sintering, but it does not eliminate internal interface between layers. So regardless of the operability of the preparation process, or thermal stress relaxation, it has great defects. And other methods, such as CVD (Chemical Vapor Deposition), high temperature plasma spraying, although can improve the internal interface to some extent, it is unstable and difficult to achieve gradient design. Tungsten copper FGM particle Co-sedimentation can achieve a continuous arrangement of heterogeneous particles and component transition, Improve or eliminate the internal macroscopic cross-section of the material, which is beneficial for structural controlling of FGM.

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